1. Field of the Invention
This invention relates to adsorbents for removing ammonia from the exhaust of diazo process printing machines and more particularly to a disposable cartridge filled with such ammonia adsorbent.
2. Prior Art
In the diazo printing process a latent image on specially coated paper is developed by exposure to ammonia vapor. The ammonia vapor has an unpleasant odor and may be harmful to human health in heavy concentrations. In order to minimize the ammonia vapor released to the atmosphere surrounding the machines by either seepage from the development chamber of the machine or transfer from the developed paper after it is removed from the machine, many diazo process machines employ blowers to draw vapor from the development chambers or exhaust chambers through which the paper is passed before it is released to the atmosphere. In large volume, heavy duty, diazo printing machines this exhaust is often vented to the exterior of the building housing the machines to minimize the exposure of operating personnel to the noxious ammonia vapor but with smaller machines this exterior venting is often impractical or uneconomical. It has been proposed that the ammonia laden exhaust from these smaller machines be passed over chemical ammonia adsorbents and then vented directly in the room housing the machine. Examples of patents disclosing venting arrangements of this type include U.S. Pat. Nos. 4,092,658; 4,167,319; 4,059,409; 3,720,150 and 3,679,369.
These chemical adsorbents become saturated with ammonia vapor over a period of use and gradually lose their effectiveness, so they must be replaced. In some systems the adsorbent is in particle or granular form and the saturated adsorbent is emptied out of an adsorbent cartridge and the cartridge is refilled from a bulk supply. This process is often inconvenient and time consuming and it is an object of the present invention to provide a more convenient and economical system for packaging, transporting and using ammonia adsorbent chemicals.